I was at a home inspection a week or so ago, the house was on a very good slope and didn’t have any real worries about drainage. The sump pump will get checked on all inspections that I can and this one was accessible. When the cover was removed there was a foul odor and the water levels were way too high (A sump shouldn’t have large amounts of standing water). Before the float was manipulated it was bypassed by plugging the pump directly into the outlet (You will see two plugs, one that plugs into the other. The first one is the float and the one that plugs into it is the sump itself). We were able to hear the water moving but barely heard the pump and the levels weren’t dropping.
When the pump was unplugged so we could check to see that it’s drain line wasn’t frozen and then plugged back in it failed to operate at all. upon further inspection the float was stuck against the side of the very deep sump.
Moral of the story is that the sump pump probably never worked and the slope was the only thing keeping the water out of the home. Check your sump pump by bypassing the float plug about every three months or at least when the seasons change. This will ensure you don’t end up with a full sump and potential damage to your home!